89 with a rebuilt 94 motor?

[sik4wheeler]

Are there any experts in my area that might want to come check it out and make a few bucks and or a free meal and some beer.

 

[sik4wheeler]

Hey guys I am home now and would like to try some things and see if i can get it to run correctly. I just re-indexed the dizzy (didn't work). I cut the ears off the dizzy and moved it while running. (it only made things worse). Can anyone give me other things to try...

 

[GSequoia]

Like I said, you need a fuel pressure gauge, it's not effective or smart to just throw parts at a problem.

 

[sik4wheeler]

fuel pressure is at 34# with key on car off and at idle but, with a little peddle applied it seems to drop to near 30#

so is 10lbs + enough to cause my problems?

 

[sik4wheeler]

Okay I just tested the injectors with a noid light and they are allspraying correctly and steady. They are speeding up as demanded.

 

[sik4wheeler]

I put a timing light on it and it appears that nothing is happening as I move the distributor around. i am going to unplug the sync sensor and give it a try again. any input??

 

[GSequoia]

Don't bother moving the distributor around, you'll just confuse the computer, as long as you index it correctly it'll be fine.

I did get the rest of the fuel pressure information when I went to the garage tonight. Spec is this:

Engine running, pressure regulator vacuum line hooked up: 31 psi
Engine running, pressure regulator vacuum line disconnected: 39 psi

Of course there's a margin of error, your 34 psi is on the high side but manageable (particularly given that it could be an inaccurate gauge too), what does it report if you unplug the regulator?

 

[GSequoia]

Some further ideas:

Try disconnecting the TPS completely and running it, what happens?

Inspect all wiring connectors to make sure a pin didn't break (it happens).

Verify your MAP sensor is correctly hooked up, this one is pretty crucial. Also where did you get the vacuum for the MAP (OEM Renix comes from the throttle body), I don't recall where I got mine when I did my HO TB swap...)

 

[sik4wheeler]

MAP vacuum comes from stock location on the 94 (a manifold port).

IIRC I did un-plug the TPS and nothing really changed.

I am starting to believe the (TIMING IS OFF) but at the timing chain

 

[sik4wheeler]

I put a timing light on the motor and #1 is firing/sparking at 16 degrees. (im not real sure on what that means though but, i bet something must be off)

 

[sik4wheeler]

Can someone give me some input before I tear apart the front of the motor???

 

[TLowery04]

i dont get paid to work on these, but ive torn down both of my '89s,

my silver one did the EXACT SAME THING after rebuilding, turned out the map sensor was bad, and the power waqs plugged in upside down because the safty snap was busted off.

I would try to get a working map on it and double check EVERYTHING for proper connections and vacuum leaks before tearing the whole thing down again.

if you have tried this already then I'm not sure where to go after that, just letting you know what i have had experiance with.

Good luck!

 

[GSequoia]

Testing your MAP sensor:

Terminal A: Ground
Terminal B: Output Voltage
Terminal C: Input (+5VDC) Voltage

NOTE: Before starting the test, check the condition of the electrical and vacuum hose connections. Repair if needed.

1: Turn the ignition switch ON (the engine should remain off), and test the voltage from connector terminal B to ground with a voltmeter. Voltage should be between 4 to 5 volts. With the engine started, warmed to normal operating temperature, and idling, the voltage output should drop to 1.5 to 2.1 volts.

2: Check for voltage at ECU electrical terminal C-6 in the same way as in step 1. The voltage readings should be the same as in step 1. If the voltages are different, then the wiring harness should be suspected as the problem area.

3: Check the supply voltage to the sensor by connecting a voltmeter to connector terminal C and a ground. Voltage reading should be 5 +/- 0.5 volts with the ignition switch ON. There should also be 5 +/- 0.5 volts at ECU electrical terminal C-14. Repair wiring harness if necessary.

4: Check the sensor ground circuit between electrical terminal A on the sensor and ECU connector terminal D-3. Connect one lead of an ohmmeter to electrical terminal A of the sensor and the other to ECU connector terminal D-3. The ohmmeter should indicate continuity. Repair wiring harness if necessary.

5: Check the sensor ground circuit at the ECU electrical connector. Connect an ohmmeter between terminals D-3 and B-11 of the ECU electrical connector. If the ohmmeter does not indicate continuity, check the sensor ground connection at the right side of the engine block at the oil dipstick mounting stud. If the ground connection is good, replace the ECU.


WARNING: If ECU connector terminal D-3 has a short to 12 volts (battery voltage), this is most likely the reason the first ECU failed; consequently, it is imperative that this circuit be repaired before installing a new ECU.

 

[sik4wheeler]

I have tested the TPS & MAP sensor voltage from the ECU and both are good. I through on a different MAP sensor and no change.

The jeep ran okay before the swap besides knocking and not a lot of power from the motor being worn out.

A friend is going to come over later tonight and plug his scanner into the jeep and check out the sensors and what not.

Does anyone have some instructions on installing a double roller timing chain. I will most likely be checking it out tomorrow since I have the day off.

 

[sik4wheeler]

Also, what does it mean when the crank is at 16 degrees and then getting spark?

 

[sik4wheeler]

Can you tell from the valves if the timing is correct or not? I already pulled the valve cover and am wandering what to look for.

 

[GSequoia]

Can you tell from the valves if the timing is correct or not? I already pulled the valve cover and am wandering what to look for.

At top dead center on the compression stroke the number one cylinder should have both valves fully closed, the TDC mark is on the harmonic balancer, if it's not right before freaking out turn it another 180 degrees to see if it's still not right

 

[sik4wheeler]

What do you mean freaking out??

I am starting to freak out.. I have tried getting it to run right a week before my first post and now I had to postpone a Rubicon trip and I am afraid that I might have to postpone another one due to it not runmomg right. my friends that drive toyotas just say damn jeep or yeah it is a jeep thing..

I know it is getting fuel and at one point or another the dizzy timing had to be correct so, I am going to be checking out the timing chain later today or tomorrow.

 

[GSequoia]

What do you mean freaking out??

I'm cautioning you not to figure it's wrong with one pass. When battling a problem sometimes it's easy to forget the small stuff, like realizing that the TDC mark can be 180 out.

 

[sik4wheeler]

Are you talking about the TDC mark on the newish harmonic balancer? If the timing on the dizzy is off it must have been right at one point since it does run and everytime I take it off I just move it forward or backward a tooth or two.

I dont think the TDC mark can be off since I am setting it to the mark everytime. Also before I put the head on the mark was at TDC and the #1 piston was at the top of the cylinder.